The present invention relates in general to lamps, and more specifically to a high performance lamp which utilizes a light source which has a glass envelope having a critical size and design specifications.
It has long been a goal and objective in the field for a low wattage, long life, short arc gap lamp which could be used in front and rear projection applications. Changing needs of the marketplace have identified the need for a short arc gap lamp in the range of 50 watts. Such an illumination source would be required to illuminate small, approximately less than 1.5 inches, light valves. This source would require a miniature source size, high luminance, good color properties, long life and low power.
To date, none of the available prior art light sources can provide the combination of the necessary small arc gap, light output and long life in the miniature size required for the above-described applications.
Prior art general service, large area lighting, metal halide lamps have been designed with very long arc gaps which make them unsuitable for precise optical control of the emitted light. These general service lamps have been utilized in projection applications, but provide extremely inefficient and costly performance. Prior art low wattage lamps have shown that metal halide arc lamps with very small arc gaps, or electrode separations, can be designed to yield very effective optical coupling, but did not yield the very high brightness or exhibit acceptable long lifetimes. The present invention provides the advantage of maintaining a very small arc gap, excellent color as associated with metal halide type lamps, long service life, high luminous brightness and low power consumption.
It is therefore an object of the present invention to overcome the problems of the prior art described above.
It is a further object of the present invention to provide a high performance illumination or light source which can be used on compact miniature light valve projection systems.
It is a further object of the present invention to provide a high performance lamp for use in systems which require miniaturization and the advantages of increased portability and lower product cost.
It is yet another object of the present invention to provide a compact miniature light source which exhibits high luminance, good color properties and long life.